The Optical Internetworking Forum (OIF) has approved Multi-Link Gearbox (MLG) 3.0, an agreement that supports 100 Gbit/s links and allows independent 10GBASE-R signals to transit physical 20 and 40 Gbit/s lanes for higher bandwidth capability.
In addition, OIF members have voted to start work on a CFP8-ACO (Analogue Coherent Optics) project, building on the CFP2-ACO implementation agreement (IA) that was approved in February this year and demonstrated operating in market-available products at OFC in March.
Under the new project, the OIF has commenced work on a new analogue coherent optics technology that supports higher baud rate and higher wavelength/carrier-count applications at higher density than the existing CFP2-ACO. The new project, dubbed CFP8-ACO, is based the existing CFP8 definition from the CFP-MSA group and provides up to 4 wavelengths/carriers per module.
In addition to a 20 W power profile, the new specification features a 9.5 mm module height, allowing for a double-stack line card or belly-to-belly, while a 40 mm module width will allow a 2 x 8 configuration for a 16 module line card. This allows for an increased number of modules as well as an higher number of wavelength/carriers.
The MLG 3.0 agreement specifies a logic layer between the Ethernet MAC and PHY layer hardware that allows the data from multiple MACs to be aggregated onto higher speed data links. This enables independent 10GBASE-R and 40GBASE-R signals to transit 4 x 25 Gbit/s and 8 x 25 Gbit/s gearboxes.
The agreement defines three MLG configurations, specifically: a 4 x 25 Gbit/s lane configuration comprised of 20 MLG lanes; an 8 x 25 Gbit/s lane configuration comprised of 40 MLG lanes; and a 2 x 20/1 x 40 Gbit/s lane configuration comprised of 4 MLG lanes (similar to 40GBASE-R) to carry up to four 10GBASE-R signals.
The OIF announced the approval of the CFP2-ACO IA for industry use earlier this year. The CFP2-ACO IA details the functionality required to perform bi-directional dual polarisation coherent optical signalling over a pair of single mode optical fibres. Such modules are expected to have applications across multiple coherent DSP ASIC generations from a variety of DSP vendors.
In March, the OIF announced it had finalised the Flexible Ethernet (FlexE) IA, designed to enable Ethernet equipment to more efficiently utilise optical link bandwidth and to bridge the gap between previous, current and next-generation rates of transmission. The FlexE IA defines a generic mechanism for supporting a range of Ethernet MAC rates that may or may not correspond to any existing Ethernet PHY rate.